What are the other Names for this Condition? (Also known as/Synonyms)

• Hypersarcosinemia
• Sarcosine Dehydrogenase Complex Deficiency
• SARD Deficiency

What is Sarcosinemia? (Definition/Background Information)

• Sarcosinemia is a rare inborn error of metabolism characterized by an increased level of the amino acid sarcosine in the blood and urine. It is reportedly most likely benign, unrelated to significant signs or symptoms
• A number of children have been detected by newborn screening and have remained symptom-free
• Some reports have associated Sarcosinemia with various symptoms including intellectual disability and other neurologic problems; growth failure; enlarged liver; cardiomyopathy; vision or hearing problems; and skeletal abnormalities
• However, whether symptoms were attributable to Sarcosinemia or were coincidental is controversial
• Sarcosinemia is sometimes caused by mutations in the SARDH gene and is inherited in an autosomal recessive manner
• It may also occur in some people with glutaric acidemia type II or severe folic acid deficiency. In some cases, the cause is unknown

(Source: Sarcosinemia; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Who gets Sarcosinemia? (Age and Sex Distribution)

• Sarcosinemia is a rare, congenital disorder. The presentation of symptoms may occur at birth
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Sarcosinemia? (Predisposing Factors)

• A positive family history can be an important risk factor, since Sarcosinemia is an inherited condition
• The condition may be seen in some individuals with the following disorders:
  • Glutaric acidemia type II
  • Folic acid deficiency (that is severe)

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Sarcosinemia? (Etiology)

• Sarcosinemia is sometimes caused by mutations in the SARDH gene and is inherited in an autosomal recessive manner
• In some cases, the cause is unknown

(Source: Sarcosinemia; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Autosomal recessive: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).

What are the Signs and Symptoms of Sarcosinemia?

A number of children have been detected by newborn screening and have remained symptom-free. Some reports have associated Sarcosinemia with various symptoms including:

• Intellectual disability and other neurologic problems
• Growth failure
• Enlarged liver
• Cardiomyopathy
• Vision or hearing problems
• Skeletal abnormalities
• Hypersacrosinemia

(Source: Sarcosinemia; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Sarcosinemia Diagnosed?

Sarcosinemia is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests
• Imaging studies
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Sarcosinemia?

The complications of Sarcosinemia may include:

• Heart abnormalities
• Liver dysfunction

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Sarcosinemia Treated?

• We are not aware of any treatment guidelines or recommendations for Sarcosinemia
• Many believe that treatment is not needed because it is assumed to be a benign condition

(Source: Sarcosinemia; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How can Sarcosinemia be Prevented?

Currently, Sarcosinemia may not be preventable, since it is a genetic disorder.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Sarcosinemia? (Outcomes/Resolutions)

• The prognosis of Sarcosinemia is dependent upon the severity of the signs and symptoms and associated complications, if any
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for Sarcosinemia:

• Sarcosinemia is also known by the following name:SARDH Deficiency

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/